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| 1. |
An electric harmonic analyser |
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Journal of the Institution of Electrical Engineers,
Volume 63,
Issue 337,
1925,
Page 69-119
J.D.Cockcroft,
R.T.Coe,
J.A.Tyacke,
MilesWalker,
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摘要:
The paper deals with the experimental harmonic analysis of electromotive force and current wave-forms. A brief outline of existing methods is given and their limitations are discussed. A modification of the dynamometer method, which allows a much higher degree of accuracy to be attained, and in which the properties of an oscillatory circuit are used to obtain a sinusoidal current wave of suitable frequency, is described. This current is passed through one coil of a dynamometer, whilst the wave to be analysed is passed through the other. The values of the coefficients in the Fourier series representing the wave-form being analysed are obtained from the readings of the dynamometer and an ammeter.The final method advocated aims at analysing waveforms up to at least the 23rd harmonic and correct to within 0.1 per cent of the fundamental. The accuracy of the method must be established by comparison with a method more accurate than the commonly employed oscillograph method, the accuracy of which is considerably improved upon. Such a standard method, which, involves the use of a synchronously driven commutator, is dealt with in detail in the first part of the paper and its own accuracy is established. Most of the principles involved are common to the two succeeding methods. A full discussion of the errors involved in the three methods is given, and the design of the necessary instruments is considered. For convenience, most of the mathematics involved is given in appendixes and only the results are quoted in the paper itself.
DOI:10.1049/jiee-1.1925.0001
出版商:IEE
年代:1925
数据来源: IET
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| 2. |
Tees-side Sub-Centre: Chairman's address. “The professional status of the engineer” |
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Journal of the Institution of Electrical Engineers,
Volume 63,
Issue 337,
1925,
Page 128-132
A.M.Paton,
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PDF (743KB)
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DOI:10.1049/jiee-1.1925.0006
出版商:IEE
年代:1925
数据来源: IET
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| 3. |
Directions for the study of unvarnished textile fabrics (including cloth, tape, webbing and yarn) |
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Journal of the Institution of Electrical Engineers,
Volume 63,
Issue 337,
1925,
Page 133-146
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摘要:
Report (Ref. AS/11) received from the British Electrical and Allied Industries Research Association.
DOI:10.1049/jiee-1.1925.0007
出版商:IEE
年代:1925
数据来源: IET
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| 4. |
A survey of automatic alternating-current protective apparatus |
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Journal of the Institution of Electrical Engineers,
Volume 63,
Issue 337,
1925,
Page 147-148
B.Nuttall,
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PDF (262KB)
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DOI:10.1049/jiee-1.1925.0008
出版商:IEE
年代:1925
数据来源: IET
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| 5. |
The effect of oxidation on the high-frequency resistance of aerial wires: with a note on measuring the resistance of thick wires |
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Journal of the Institution of Electrical Engineers,
Volume 63,
Issue 337,
1925,
Page 149-153
L.B.Turner,
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摘要:
Measurements are made on thick solid and stranded wires to ascertain the effect on their high-frequency resistance of the oxide film formed by weathering. It is found that the weathering produces no sensible effect, under either dry or wet conditions.The several methods of measuring high-frequency resistance are compared in respect of their suitability for determining the resistance of stout straight conductors.
DOI:10.1049/jiee-1.1925.0009
出版商:IEE
年代:1925
数据来源: IET
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Volume 63 issue 337